Battery terminal clamp



Aug. 1, 1933. s, E. CARLSON 1,920,543

BATTERY TERMINAL CLAMP.

Filed Feb. 26, 1930 4/ 1 L l im- 1MP? Ill 37 Sagzg 2 Elarlson HA L H 1 42 g e Patented Aug. 1, 1933 UNITED" STATES 1,920,548 BATTERY TERMENAL CLAMP Samuel E. Carlson, Alhambra, Calif. Application February 26, 1930; Serial No. 431,474

6 Claims.

My inventionis an improved typeofterminal clamp. useful in establishing electrical connection between a cable or other suitable electrical conductor, anda terminal postof a storage hattery..

An object of the. invention is' to provide'a ter ininal clamp in which means are provided for tightening the clamp into physical and electrical engagement with a terminal postor equivalent structure, and in which the tightening means are disposed at a relatively remote point from the terminal post, thereby. removing the tightening means from that'locality in which corrosion occurs during normal use oi a storage battery.

A further object is to provide a terminal. clamp in which the tightening means are movable after having been tightened thereby, making itpossible to first secure the clamp in operative position and subsequently move the tightening means to a position wherein it does not project from the battery. Similarly, when it is desired to remove the clamp, the tightening means may be swung from retracted position into aposition wherein access to the tightening means is more convenient.

Another object is to provide a terminal clamp of the generalcharacter described, which is ex 'ceedingly simple in construction, being composed of relatively few and simple parts, andhence which is relatively inexpensive to manufacture.

the clamp is fully capable of operatingwitha high. degree of efficiency in securely maintaining physical and electrical engagement betweenthe electrical conductor. and the terminal post.

A still further object is to provide a terminal clamp adapted to be tightened through the expedient of a pair of opposed levers movable about a fulcrum which is adjustable to permitproper installation of the levers in conjunction with terminal posts of various sizes. g

The invention possesses. other, objects and advantageous features, some of which, withithose enumerated,.will be set forth in the following description of theinventions particular embodi- 'ment which is illustrated in the drawing accompanying and forming a part of the specification.

' Referring to the drawing:

Figure 1 is a-perspective view of a portion of a storage battery showing one of my terminal clamps operatively installedthereupon.

Fig. 2 is a top plan View with portions of the figure broken away.

Fig. 3 is a side elevation of the clamp. This r view may be considered as a vertical sectional .view

taken upon theline 33 of Fig. 2, with the, direction of View as indicated. The dashed lines indicate the position into which the tightening means maybe swung to facilitate tightening or loosen ing the clamp. 6 Fig. 4 is an enlarged vertical, transverse sec- In spite of this economical construction however,

tional view taken upon the line 4-4 of Fig. 2, with the direction of View as indicated.

In terms of broad inclusion, the devic'eof the present invention comprises a member towhich an electrical conductor is permanently attached as by soldering or Welding-this member having means engageable with a terminal post such as that commonly employed upon a storage battery.

Tightening means are 'associa'tedwith the member in such a manner that it may be securely when in a more accessible position than when retracted. Y 1 I Whereasthe device-of the present'inventionis capable'of establishing physical and electrical contact 1 between a conductor and substantially any type' of terminal post, it is'herein shown and described as being particularly adapted for use in conjunction with a terminal post 6 of thetype commonly employedupon a storage battery 7. A'clamp used in such service must be especially efiicient, becauseof the fact that one of the most common uses for a storage battery-is upon vehicles "such as automobiles, wherein" it is subjected tosevere' shocks and vibration tending to loosen the engagement between the clamp and the post 6, with a consequent tendency to establislran 'inefiicient electrical joint therebetween. Furthermore, such use of a storage battery results in an accumulation of grease and dirt upon the terminal posts and clamps associated there- "with, which not only have a tendency to decrease the efficiency of the electrical connection there- "between, but also to make it difficult to tighten the clamp upon the terminal post, and to remove it therefrom. It is with these circumstances of use, of'a storage battery terminal clamp in mind, I

. that the. device of the present invention has been developed in an efiort to obviate such undesirable conditions. g g

In my improved terminal clamp, the element which engages the terminal post 6, is in the form 'of 'a substantially U-shaped clamping. member 8 comprising spaced arms 9 and 11, joined atone end by the same metal 12 which units the'arms 9 and 11 to asocket member 13 within which an .end of an electrical cable 14 may be securely at- .tached. It is intendedthat the cablell be persoldering or welding is most conveniently employed for this purpose.

The inner faces of the arms 9 and 11 adjacent their bases, are rounded to define a substantially cylindrical socket 16. The outer ends 17 and 18 of the arms 9 and 11 arespaced slightly from each other however, when the arms 9 and 11 are tightened against the post 6, the purpose being to cause pressure exerted against the outer faces of the arms 9 and 11 at their outer ends, to increase the tightness of the engagement of the clamping member 8 upon the post 6. Aligned holes 21 and 22 are formed transversely ofthe outer ends 17 and 18 respectively, of the arms 9 and 11.

The structure thus far described, is the conventional terminal post clamp now universally employed, and my invention lies not in the construction of this element, but in the tightening means hereinafter to be described, and in the adaptation of my improved tightening means to the post clamp.

This tightening means takes the form of a pair of opposed levers 26 and 27 preferably similar in construction. Each lever is preferably channel-shaped in cross-sectional configuration, having a bottom web 28 and side flanges 29. However, inasmuch as in the present modification, the tightening force for the levers 26 and 27, is applied thereto intermediate their ends, I prefer to form the flanges 29 considerably higher at the center of each lever than at the ends thereof, thus increasing the cross-sectional area of each lever, and consequently, the rigidity thereof, at the point of greatest bending moment.

A slight projection 31 is formed on the inner face of each lever; 26, 27, adjacent the inner end thereof. These projections 31 are receivable within the holes 17 and 18 of the arms 9 andll, with the result that these holes serve as sockets within which the projections 31 may be received to pivotally support the levers 26 and 27 upon the arms 9 and 11 respectively, for pivotal movement about a common axis normal to the engaging faces of the levers and arms. The projections 31 may be constructed most easily by pressing a portion of the metal of which the levers are constructed, outwards from the, web 28 of each lever 26,27, adjacent the inner end thereof.

An adjustable fulcrum is interposed between the outer ends of the levers 26 and 27. In its preferred form, this fulcrum is in the formof a bolt 32 extending through aligned holes 33 in the,

webs 28 of the levers 26 and 27 adjacent the outer ends thereof. A pair of nuts 34 and 36 are threaded upon thebolt 32, each of these nuts being positioned to engage the innerface of one of the levers 26, 27. Obviously, therefore, the effective spacing between the outer ends of. the levers, may be varied by altering the position of one or both of the nuts 34, 36, upon the bolt 32.

A tightening bolt 37 extends through aligned holes 38 in the webs 23 of the levers 26 and 27 between the fulcrum bolt 32 and the projections 31. Preferably the bolt 37 is a carriage bolt having a. non-circular portion 39 immediately under the head 41 thereof, this non-circular portion being fitted between the flanges 29 of one of the levers 26, so as to prevent thebolt from turning when the nut 42 which is threaded thereupon, is turned. The nut 42 is disposed upon the opposite side of the other lever 27 from that which is engaged by the head 41, so that when the nut 42 is tightened, the inner ends of the levers 26 and 27, i. e., the ends which engage the arms 9 and 11, will be forced together. I also preferably employ a washer 43 interposed between the nut be used to supplant the ordinary bolt which is commonly passed through the aligned holes 21 and 22 in the ends of the arms 9 and 11 of the conventional terminal clamp. After this conventional bolt has been removed from the holes and 22, the levers 26 and 27 should be mounted upon the arms with the projections 31 seated within the holes 21 and 22. The device should then be positioned upon the terminal post 6 with which it is desired to establish electrical connection to the cable 14 which previously has been secured within the socket member 13. This is done by slipping the arms 9 and 11 downwards over the terminal post 6, to seat the terminal post within the socket l6-it being understood that the nut 42 is sufficiently loose to permite of so doing. The nut 42 may then easily be tightened with the levers 26 and 2'? extending vertically from thetop of the battery 7, which, of course, disposes the nut 42 in a more convenient position to permit engagement thereupon, of a wrench. Inasmuch as the bolt 37 is disposed between the fulcrum bolt 32 and those ends of the levers which engage the arms 9 and 11, this tightening of the nut 42 upon the bolt 37, will result in pressing the arms 9 and 11 tightly against the post 6, to prevent inadvertent displacement thereof through vibration, and to insure an efficient electrical conwhich should be preserved for other elements.

It should be observed that the bolt 37 and the nut 42 are spaced at a more remote position from 12 the terminal post 6, from that occupied by a bolt which extendsthrough the holes 21 and 22 in the conventional manner. It is well known that during the customary use of a storage battery, corrosion develops at the terminal posts, and more 5 particularly at the positive terminal post. However, by positioning the bolt 37 and its nut 42 more remotely from the terminal post, removal of the terminal clamp from the post is facilitated because or the fact that the bolt 37 andnut 42 are positioned outside that locality at which the corrosion develops.

The adjustability of the fulcrum bolt 32 permits of installation of the tightening means upon clamping members 8 of various sizes. The nuts 34 and 36 should be so positioned upon the fu1-, crum bolt 32 that the levers 26, 27, are disposed in substantially parallel arrangement when the clamp is tightened, thus securing the firmest engagement of the levers 26 and 27 upon the arms 9 and 11.

It should also be observed that the clamp may be tightened by first setting the nut 42 in proper position upon the bolt 37, and then adjusting the nut 34 and/or 36 so as to increase the distance therebetween, and force the outer ends of the levers 26 and 27 apart. When so used, the levers are of the first class, inasmuch as the bolt 37 which acts as the fulcrum, is positioned between the work and the point of. application of the force.

Under certain circumstances, this manner of us ing the device may offer greater convenience because of the greater distance of the nuts 34 and" 36 from any surfaces which might interfere with the manipulation of a wrench.

It is to be unedrstood that the details of the embracing a terminal post, a lever associated with each of said arms, one end of each lever being pivotally joined to the associated arm for rotary movement about an axis normal to the engaging faces of said arm and lever, a fulcrum interposed between said levers, andmeans for forcing said levers toward each other.

3. A terminal clamp comprising a pair of arms embracing a terminal post, a lever associated with each of said arms, one end of each lever being pivotally joined to the'associated arm for rotary movement about an axis normal to the engaging faces of said arm J and lever, a fulcrum interposed between said levers adjacent the other ends thereof, a bolt extending through both levers between said fulcrum and said arms, and means for tightening said bolt.

4. A terminal clamp comprising a pair of arms embracing a terminal post,'each arm having a socketin the outer face thereof, a lever associated with each of said arms, each of said levers having a projection on its inner face receivable within the associated socket, a fulcrum interposed between said levers, and means for forcing those portions of the levers engaging the arms toward each other.

5. A terminal clamp comprising a pair'of arms having a passage therebetween-adapted to receive the terminal to be clamped, a pair of levers engaging said arms, at least one of said levers being of channel-shaped cross section with its flanges extending from its web in a direction away from the other lever, a bolt passing through .both levers and having a non-circular portion disposed between said flanges to hold said bolt from turning, and a nut threaded upon said bolt beyond saidother lever.

6. A terminal clamp-comprising a pair of arms having a passage therebetween adapted to receive the terminal to be clamped, a pair of levers engaging said arms, at least one of said levers being of channel-shaped cross section with its flanges extending from its web in a direction away from the other lever, a bolt passing through both levers and having a non-circular portion disposed between said flanges to hold said bolt from turning, and a nut threaded upon said bolt beyond said other lever, said levers being pivotally'engaged with said arms. to dispose said nut optionally in accessible position or in retracted position.

' SAMUEL E. CARLSON. 

